Chore: Update Python SDK compatibility. (#3474)

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## About the changes
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Update to Python compatibility table. 

* Impression events supported in v5.6.0.
([Docs](https://docs.getunleash.io/unleash-client-python/eventcallbacks.html))
* Bootstrapping from files and custom boostrapping has been supported
since v5.2.0.
([Docs](https://docs.getunleash.io/unleash-client-python/filecache.html)
&
[Docs](https://docs.getunleash.io/unleash-client-python/customcache.html))

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website/docs/reference/sdks/index.md

@@ -98,10 +98,10 @@ If you see an item marked with a ❌ that you would find useful, feel free to re
 | Can disable metrics | ✅ | ✅ | ✅ | ✅ | ✅ | ✅ | ✅ | ✅ |
 | Client registration | ✅ | ✅ | ✅ | ✅ | ✅ | ✅ | ✅ | ✅ |
 | Basic usage metrics (yes/no) | ✅ | ✅ | ✅ | ✅ | ✅ | ✅ | ✅ | ✅ |
-| [Impression data](../impression-data.md) | ⭕ | ✅ | ⭕ | ⭕ | ⭕ | ⭕ | ✅ | ⭕ |
+| [Impression data](../impression-data.md) | ⭕ | ✅ | ⭕ | ✅ | ⭕ | ⭕ | ✅ | ⭕ |
 | **Category: Bootstrap (beta)** |  |  |  |  |  |  |  |  |
-| Bootstrap from file | ✅ | ✅ | ✅ | ⭕ | ✅ | ✅ | ✅ | ⭕ |
-| Custom Bootstrap implementation | ✅ | ✅ | ✅ | ⭕ | ✅ | ✅ | ✅ | ⭕ |
+| Bootstrap from file | ✅ | ✅ | ✅ | ✅ | ✅ | ✅ | ✅ | ⭕ |
+| Custom Bootstrap implementation | ✅ | ✅ | ✅ | ✅ | ✅ | ✅ | ✅ | ⭕ |
 
 ## Community SDKs ❤️ {#community-sdks}